Honesty can be an all too elusive commodity in football but Patrice Evra prides himself on his candour.

After helping a largely second-string Manchester United side record their biggest Premier League win of the season, he advanced an interesting theory as to why it has taken David Moyes's team so long to dispense such a domestic thrashing.

"In the Champions League we've played good, we're confident and it looks like we're all up for it, more than in the League and the English cups," said Evra, his mind turning to Wednesday's all-important quarter-final second leg at Bayern Munich, where he hopes to start at left-back. "I know it's not professional to say that but it's the truth. We look more on it, we look more like we have the Man United spirit, when we play in the Champions League."

Welcome as openness generally is, some things are best kept private and even Evra turned coy, and slightly cryptic, when asked about the reasons behind an anomaly that has left Moyes's players travelling to Munich with the score from the first leg a commendable 1-1 but as rank outsiders to finish in the Premier League's top four. "I have the answer," he said. "It's difficult, really painful. Sometimes you have to let the storm pass. We have to make sure we're ready for next year."

Goodness knows what the score might have been here had United adopted a Champions League mindset. As it was, a wretched Newcastle United simply could not handle the excellent Juan Mata – ineligible for Europe – let alone, the influential, technically superior, Shinji Kagawa and Adnan Januzaj.

Imperious as Mata proved, deployed in a classic No10 role, Cheik Tioté – who appeared to have been detailed to mind him – endured a shocker, offering pitiful resistance. With Fabricio Coloccini, Newcastle's key centre-half, possessing no answers either, Alan Pardew's job security was left looking fragile after a run that has resulted in his team conceding 11 goals and scoring none in the last three games. This was the sixth time since early February they have lost by a three or four-goal margin.

The difference between the teams was that the visitors – Mata, Kagawa and the industrious Darren Fletcher, in particular – clearly craved Moyes's attention. No matter that Marouane Fellaini experienced another off day, leaving his manager joking that the £27m midfielder had suffered a "dizzy spell", and might have been sent off for apparently elbowing Dan Gosling; Fletcher held central midfield together.

"Players went out there trying to prove a point and impress the manager," said a player happily recovered from a debilitating bowel condition. Fletcher was especially anxious to laud a Chelsea import who opened the scoring, courtesy of a curling free-kick, and added the second after deceiving Coloccini by switching feet before rolling the ball beyond Rob Elliot.

"Juan controls the pace of games," he said. "He has an eye for a killer pass. He's a really intelligent footballer. It's been a disappointing season in the league but if Juan can show this sort of form we can really get back to challenging for the title next season."

After Kagawa's pass created the third goal for Javier Hernández, Mata's clever backheel preceded Janzaj shooting the fourth. It left United with the division's best away record and Moyes acknowledging that the "expectation" at Old Trafford had something to do with his side's often disappointing and self-destructive home form. Pardew knows all about a much more pronounced version of that syndrome. Newcastle's manager can only be grateful that the injured Robin van Persie and Wayne Rooney – who Moyes hinted should be fit for Munich – were not around to exacerbate his woes.

Unlike Evra, Pardew is both unwilling and unable to be honest. He does not want to upset Mike Ashley, Newcastle's owner, by saying he has been badly let down in the transfer market, so he instead blamed this latest reverse on two factors: a mini injury crisis and a controversial belief that the set-piece prefacing Mata's opener should not have been awarded.

The reality is that he is struggling to motivate a team that, incredibly, remain in ninth place and he has clearly fallen out with Newcastle's most creative, and gifted, individual Hatem Ben Arfa. Then there is his bewildering reliance on an overly direct playing style within a narrow 4-4-2 formation.

"I've never experienced a run as bad as this," Pardew conceded. "We need to improve in every way. We need to get ourselves focused."

How he could do with Evra and his increasingly rare candour in an unhappy Tyneside dressing room. "When you're not doing well you have to accept criticism," said the Frenchman. "Of course it hurts but sometimes you deserve it."